概要

SwingアプリケーションのLookAndFeelagentを使って外部から切り替えてデバッグします。

LookAndFeelDebugAgent.png

ソースコード

package swinghelper;
import java.awt.*;
import java.awt.event.*;
import java.lang.instrument.*;
import javax.swing.*;

public class LookAndFeelDebugAgent {
  public static void premain(String args) throws Exception {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        createAndShowGUI();
      }
    });
  }
  public static void createAndShowGUI() {
    ButtonGroup group = new ButtonGroup();
    Box box = Box.createVerticalBox();
    for (LookAndFeelEnum lnf: LookAndFeelEnum.values()) {
      JRadioButton rb = new JRadioButton(new ChangeLookAndFeelAction(lnf));
      group.add(rb); box.add(rb);
    }
    box.add(Box.createVerticalGlue());
    box.setBorder(BorderFactory.createEmptyBorder(5, 25, 5, 25));

    JFrame frame = new JFrame("LnF");
    frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
    frame.getContentPane().add(box);
    frame.pack();
    frame.setVisible(true);
  }
  private static enum LookAndFeelEnum {
    Metal  ("javax.swing.plaf.metal.MetalLookAndFeel"),
    Mac  ("com.sun.java.swing.plaf.mac.MacLookAndFeel"),
    Motif  ("com.sun.java.swing.plaf.motif.MotifLookAndFeel"),
    Windows("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"),
    GTK  ("com.sun.java.swing.plaf.gtk.GTKLookAndFeel"),
    Nimbus ("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
    private final String clazz;
    private LookAndFeelEnum(String clazz) {
      this.clazz = clazz;
    }
    public String getClassName() {
      return clazz;
    }
  }
  private static class ChangeLookAndFeelAction extends AbstractAction {
    private final String lnf;
    protected ChangeLookAndFeelAction(LookAndFeelEnum lnfe) {
      super(lnfe.toString());
      this.lnf = lnfe.getClassName();
      this.setEnabled(isAvailableLookAndFeel(lnf));
    }
    private static boolean isAvailableLookAndFeel(String lnf) {
      try {
        Class lnfClass = Class.forName(lnf);
        LookAndFeel newLnF = (LookAndFeel) lnfClass.newInstance();
        return newLnF.isSupportedLookAndFeel();
      } catch (Exception e) {
        return false;
      }
    }
    @Override public void actionPerformed(ActionEvent e) {
      try {
        UIManager.setLookAndFeel(lnf);
      } catch (Exception ex) {
        ex.printStackTrace();
        System.out.println("Failed loading L&F: " + lnf);
      }
      for (Frame f: Frame.getFrames()) {
        if (f instanceof JFrame) {
          SwingUtilities.updateComponentTreeUI(f);
          f.pack();
        }
      }
    }
  }
}

解説

Look And Feelを切り替えるためのパネルが一緒に起動し、対象アプリケーションのソースコードを変更することなく、LookAndFeelの変更をテストすることが出来ます。

javaagentを使うので、JDK 1.6以上で以下のように起動します。

java -javaagent:lnfagent.jar -jar example.jar

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